Boris Johnson signs the Declaration of Acceptance of Office to be Mayor of London at City Hall in London. Photo: Stefan Rousseau/PA Wire

In a result which most people expected but which turned out to be a lot closer than many thought, Mr Johnson was given a second term at City Hall when the gruelling election came to an end earlier this morning.

He polled 1,054,811 votes to Ken Livingstone’s 992,273.

Today, the Mayor said: “I think people were listening to what we had to say about taxes, getting rid of all sorts of unnecessary expenditure, putting it where people want to see it.

“It was a very hard-fought long campaign.”

Signing the declaration of office at City Hall, Mr Johnson said the election had given him a mandate to go forward with the controversial automation of the Tube.

Watched by Met Police commissioner Bernard Hogan-Howe, he added the result also gave him a mandate to keep police numbers high.

He promised to “work his socks off” and stand up for London in Whitehall.

Interviewed on LBC radio, Mr Johnson was asked if he would attempt to be re-elected to parliament in two or three years’ time, allowing him to position himself as a future Tory leader.

He replied: “I’m going to say this categorically that the answer to that is no, I don’t want to do that. I want to discharge my mandate and my duty.”

Mr Johnson’s father Stanley refused to rule out the possibility of his son as future leader saying: “Who knows?”

Asked by the BBC why Boris bucked the national trend, he said: “Because he had the charisma and because people believe he is a man that says what he means and he does what he says and that’s something that counts.”

Prime Minister David Cameron said he was “delighted” by Mr Johnson’s mayoral victory.

Speaking at City Hall, Mr Cameron said “I think it was a very strong campaign by Boris. It was based on his record, on the excellent things he has done out there and I am delighted to congratulate him.

“It was a campaign the whole Conservative party got behind.

“I enjoyed campaigning for Boris but now what matters is working together for the good of London, as PM, as Mayor, and that is exactly what we are going to do.”

Up at The O2 has teamed up with London24 to give one lucky reader the chance to experience urban mountaineering this summer with an exhilarating 90-minute climb across the roof of one of London’s most iconic landmarks.